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WorksheetsPraxis II: Biology Exam
Total questions: 160
Worksheet time: 1hrs 25mins
In a plant, undifferentiated cells that can divide throughout the life of the plant to enable growth are found in which of the following?
Cortex
Meristem
Pith
Dermis
Which of the following characteristics of a material found on the bark of a tree will most likely prove that the material is a living thing?
The material is green.
The material appears to reproduce on its own.
The material is composed primarily of carbon and hydrogen atoms.
The material absorbs heat in the presence of sunlight.
Given the DNA sequence 5' ATGCCCTCA 3', which of the following is the correct complementary sequence of messenger RNA?
3' U A C G G G A G U 5'
3' A C T C C C G T A 5'
5' A U G C C C U C A 3'
5' T A C G G G A G T 3'
According to evolutionary theory, which of the following individuals has the greatest Darwinian fitness?
A man who lives to be 70 years old, has no children and remains very healthy until just before his death
A man who lives to be 50 years old, has 4 children and 16 grandchildren and is ill for five years before his death
A woman who lives to be 80 years old, has 6 children and 30 grandchildren and is in poor health most of her life
A woman who lives to be 90 years old, has 1 child and no grandchildren, and is ill for four years before her death
When caribou migrate, the weaker ones often become the prey of wolves and other carnivores. If the vegetation that the caribou eat is sparse for several consecutive years, which of the following will most likely be true about the wolf population during that same period?
The wolf population will initially increase because of an increase in the wolves' food availability.
The wolf population will initially decrease because the wolves compete with the caribou for the same food.
The wolf population will initially decrease because the stronger caribou begin to use the wolves as a food source.
The wolf population will not change significantly; only the caribou population will decrease.
Which TWO of the following are scientific theories?
Energy can be neither created nor destroyed but can change in form.
Evolutionary adaptations arise by natural selection.
Water covers 71% of Earth’s surface.
The number of species in an isolated island-like habitat is determined by an equilibrium between the rates of immigration and extinction.
A diploid organism has the genotype AaBbCc for three loci, each of which is located on a different chromosome. A normal gamete produced by this organism could have which of the following genotypes?
AbC
AB
AaB
ACc
Which of the following amino acids can contribute to the three-dimensional structure of a protein by forming covalent bonds with an identical amino acid in another part of the protein?
A
B
C
D
The action potential will not occur, because depolarization will not occur.
The membrane will depolarize more quickly, and the action potential will be of shorter duration.
The membrane will repolarize more slowly, and the action potential will last longer.
Development of an action potential does not require sodium; therefore the action potential will remain unchanged.
Sea star wasting syndrome is decimating some populations of sea stars along the North American Pacific coast. Sea stars are the only natural predator of sea urchins and mussels in some portions of this ecosystem. Which of the following is most likely a concern of scientists studying the ecosystem?
The wasting syndrome will spread to all other animals in the ecosystem.
Without sea stars, the sea urchins and mussels will start to feed on each other.
An existing species in the ecosystem will move into the dietary niche of the sea stars.
Without sea stars, the sea urchin and mussel populations will increase and eliminate other species in the ecosystem.
Which of the following statements regarding the water cycle is correct?
On a global scale, there is a net movement of water vapor from the land to the oceans.
On a global scale, evaporation exceeds precipitation over the land.
The water cycle differs from other biogeochemical cycles because most water moves through ecosystems by physical rather than chemical processes.
Transpiration by terrestrial plants directly produces surface runoff and groundwater movement from the land to the oceans.
The skeletal structures of the human arm and whale flipper (pectoral fin) are shown above. The arm and flipper are examples of
analogous structures
homologous structures
the results of convergent evolution
the results of sympatric speciation
Which of the following is required to initiate transcription of a particular gene in eukaryotic cells?
An RNA polymerase is associated with transcription factors bound to the gene's regulatory sequences.
A helicase enzyme makes the gene accessible by separating the two strands of the chromosome.
Splicing factors remove the introns of the gene and join the exons.
An RNA polymerase recognizes and binds to the initiation codon of the gene.
Investigators have immunized a rabbit with Substance P. They are studying the effect of the immunization on the production of anti-Substance P antibodies over a two-week period following the immunization. Which of the following is the best hypothesis for the experiment?
Rabbits produce antibodies in response to immunization with Substance P.
Antibody production by the rabbit in response to Substance P will increase over a two-week period.
Immunization with Substance P will not affect antibody production over a two-week period.
Immunization with Substance P stimulates the immune system of rabbits.
Increasing the light intensity
Misting the leaves with water
Removing half of the leaves
Placing the experimental setup inside a sealed, clear glass container
Aphids are small insects that rest on the stems and leaves of plants and insert their needlelike mouthpiece directly into the phloem of the plants. Which of the following is the primary reason that an aphid infestation will kill a plant?
Aphids prevent normal water transport throughout the plant.
Aphids deplete the sugars normally available for the plant.
Damage to the phloem reduces transpiration levels.
Damage to the phloem prevents photosynthesis.
Skin color in humans appears to show a continuous distribution. In an examination of pedigrees, no recognizable pattern of Mendelian inheritance is found with respect to skin color. The data suggest that inheritance of skin color in humans is
codominant
epistatic
incompletely dominant
polygenic
Wind turbines are used for which of the following activities?
Maintaining a breeze over crops growing in an arid environment without using a lot of farm machinery
Generating electricity without burning fossil fuels
Pumping natural gas without injecting chemicals into groundwater
Circulating water and nutrients in some seas without installing ocean floor pumps
Behavioral biologist Konrad Lorenz noticed those baby geese considered him to be their mother if he was the first image they saw immediately upon hatching. The baby geese were exhibiting which of the following behaviors?
Habituation
Trial and error
Territoriality
Imprinting
Chlamydomonas reinhardtii is a unicellular green alga that has a diameter of approximately 10 microns. 10 microns is equivalent to
0.01 cm
0.001 inch
0.01 mm
10–6 m
Which TWO of the following processes occur as part of DNA replication?
Polymerases proceed in a 5' to 3' direction along the template strand.
One new strand is synthesized continuously, and one new strand is synthesized as a series of Okazaki fragments.
A polymerase synthesizes RNA primers.
As the replication enzymes proceed along a DNA molecule, the two strands separate and then reanneal.
On a global level, which of the following account(s) for the greatest annual use of freshwater?
Urban megacities
Agriculture
Industrial manufacturing
Wastewater treatment
Which of the following statements about the acrosome of a human sperm is correct?
It provides ATP for moving the flagellum.
It is involved in fusion of the male and female pronuclei.
It contains enzymes to help the sperm penetrate the egg.
It is located at the base of the flagellum of the sperm.
An individual with the genotype AabbccDd mates with an individual with the genotype AabbCCDd. Which of the following is the expected frequency of offspring with the genotype AaBbCcDd ?
0
1/8
1/4
1/2
Which of the following is associated with pioneer species?
Understory community
Climax community
Late succession
Primary succession
A mature ovum produced from division of a primary oocyte has 18 chromosomes. How many chromatids were present in the primary oocyte during prophase I of meiosis?
18
36
72
144
Bacterial samples were counted every hour from a flask being incubated at 37°C on a shaker. Which of the following was most likely being studied?
The number of conjugating bacteria
The cell wall structure of bacteria
The pathogenicity of bacteria
The growth rate of bacteria
Which of the following is true about nonvascular plants, such as mosses?
The sporophyte is dependent on the gametophyte for nutrients and water.
Reproduction typically occurs asexually by the formation of stolons.
They only perform anaerobic cellular respiration.
They fix nitrogen directly from the atmosphere.
Which of the following is a true statement about the disposal of aluminum soda cans?
Aluminum cans should be recycled because aluminum is a scarce element in Earth's crust.
Aluminum cans should be recycled because processing of aluminum ore requires a lot of energy.
Aluminum cans break down easily to contaminate groundwater surrounding a landfill.
Aluminum cans are coated with lead-based paints that can leach into groundwater surrounding a landfill.
MNOP
NOPM
P N O M
O M N P
Polymerase chain reaction (PCR) is a technique used to amplify small amounts of DNA for further study. Which of the following is (are) a key component used in PCR?
Reserve transcriptase
Restriction enzymes
DNA ligase
DNA primers
Which of the following best describes punctuated equilibrium?
The forward and reverse directions of a reaction are in equilibrium unless there is an external input of reactants or products.
Long periods of evolutionary stability are followed by periods of rapid speciation.
Water accumulates in the contractile vacuole of certain organisms that live in a hypoosmotic environment, but the organisms remove the excess water by periodically contracting the vacuole.
All organisms in an ecosystem are in equilibrium unless a change occurs to a particular biotic or abiotic factor.
Which of the following must take place for ecological succession to occur in a given area?
The organisms living there at a given time must alter the environment.
The climate must change during the process.
The pioneer organisms must be better adapted to the environment than the climax community is.
The process of evolution must continually produce new species to fill available niches.
Which of the following is a correct practice when using a light microscope?
Only the coarse adjustment knob should be used to focus on a specimen when using a high-power objective.
A drop of oil should be placed on a coverslip before viewing a specimen with any objective.
A specimen on a slide should be first brought into focus by looking through the ocular lens while bringing the objective lens closer to the slide.
A specimen on a slide should be located and brought into focus by first viewing it with a low-power objective.
A difference between plants and fungi is that plants
have cell walls
are multicellular eukaryotes
are autotrophic
are decomposers
In individuals with a particular neurodegenerative disorder, physical and behavioral symptoms first appear when the individuals are in their 30s or 40s. The disorder is inherited in an autosomal dominant fashion and is caused by a particular gene with an excessive number of repeats of the trinucleotide sequence CAG. The disorder is most likely which of the following?
Turner syndrome
Huntington’s disease
Down syndrome
Rheumatoid arthritis
Turner syndrome
Huntington’s disease
Down syndrome
Rheumatoid arthritis
Biological magnification
Cultural eutrophication
Resource partitioning
Ecological succession
Which of the following best describes the role of buffers in living systems?
Regulating blood glucose levels
Controlling levels of growth hormone in the blood
Combining with excess H+ and OH– ions in solution
Activating anaerobic respiratory pathways
Special infoldings are present on the respiratory surfaces of most terrestrial animals. This adaptation is useful because
external respiratory organs would invite attack from predators
gas exchange requires a thin, moist membrane of sufficient surface area to meet the requirements of the animal
gas exchange requires the use of circulatory pigments
gas exchange is less efficient on land than in aquatic environments
On Earth, which THREE of the following are major reservoirs of carbon?
Limestone
Oceans
Sediments of aquatic ecosystems
Polar ice caps
Which of the following organelles can synthesize some of its own proteins?
Golgi apparatus
Nucleus
Endoplasmic reticulum
Chloroplast
A high school student is seeking background information for the discussion section of a lab report. Which of the following will provide the most reliable and current information?
A lesson taught by the student’s teacher
A science blog on the Internet
A recent research paper in a scientific journal
The class textbook
child is born to a man who has red‑green color blindness and a woman who has full color vision, whose father had red‑green color blindness. Red‑green color blindness is an X‑linked recessive trait. The chance that the child is a carrier of red‑green color blindness is
0%
25%
50%
75%
The release of carbon dioxide during the burning of fossil fuels has contributed to which of the following environmental problems?
Glabal Warming
Acid precipitation
A decrease in chemical weathering
The loss of nonrenewable resources
Which of the following is most likely to occur when double-stranded DNA is heated in the laboratory as part of the polymerase chain reaction (PCR) technique?
The DNA will coil tightly around histones.
The DNA will decompose and be transformed into RNA.
The DNA will separate into two strands as the hydrogen bonds are broken.
The DNA will become more stable because of an increased number of hydrogen bonds.
Mutation
Conjugation
Transformation
Transduction
A researcher collects what appears to be a new species in a freshwater stream. Microscopic analysis shows the presence of chloroplasts, mitochondria, a defined nucleus, and a cellulose-based cell wall. Individual cells cluster to form colonies, but the colony lacks any true tissue or organ formations. This new species most likely belongs in which of the following kingdoms?
Animalia
Fungi
Protista
Monera
The use of recombinant DNA technology to create a vaccine for which of the following pathogens has provided the most widespread benefit to individuals in the United States?
Hepatitis B virus
Variola (smallpox) virus
Streptococcus pneumoniae
Mycobacterium tuberculosis
In which of the following cell types is a mutation most likely to have an impact on the gene pool of a population?
Liver
Neurons
Skin
Sperm
Four percent of an isolated population suffers from an autosomal recessive genetic disease. Assuming the population is in Hardy-Weinberg equilibrium for the trait in question, what percent of the population are carriers?
2%
16%
32%
68%
Which of the following is the most appropriate method for safely handling an acid spill in a laboratory?
Neutralizing the acid with a 5 M sodium hydroxide (NaOH) solution
Diluting the acid with water
Wiping up the acid with paper towels
Soaking up the acid with an acid-neutralizing absorbent pad
Which of the following describes the primary function of bone marrow in humans?
It is the site of O2 and CO2 exchange.
It is the source of new blood cells.
It is the site of tendon attachment.
It is the source of hormones that control bone growth.
In photosynthesis, light energy is converted to chemical energy with an efficiency of approximately
100%
33%
5%
1%
Which of the following describes a mechanism by which tumor-suppressor proteins prevent cells with DNA mutations from becoming cancer cells?
The interaction between cyclins and cyclin-dependent kinases is blocked, which halts cell division.
Binding between growth factors and growth factor receptors on the surface of the cells is blocked, and the cells lyse.
The tumor-suppressor proteins bind to the spindle apparatus and interfere with chromosome movement, which blocks cell division.
The tumor-suppressor proteins trigger the cells to dedifferentiate to stem cells.
Scientists have proposed that echinoderms and chordates form a monophyletic group because they share a recent common ancestor. Which of the following evidence best supports this proposal?
Both groups are characterized by segmentation during embryonic development.
The two groups have similar patterns of embryonic development.
In both groups, the early embryo shows spiral cleavage.
In both groups, three embryonic germ layers develop during gastrula formation.
Which of the following structures will most likely be damaged if there is an injury to the cells of the endoderm during embryogenesis?
Nervous System
Skin
Stomach Lining
Heart
In a particular ecosystem, the number of bobcats has been approximately the same for the past ten years. Which of the following best explains why the number of bobcats has not changed significantly over the ten-year period?
Bobcats have a very long reproductive cycle.
The bobcat population is at carrying capacity.
The mutation rate within the bobcat population is very low.
Bobcat immunity to disease has increased over the ten-year period.
A study measuring the effect of drug Q on stomach pH was conducted on 120 individuals. An additional 120 individuals received a saline solution instead of drug Q. The averaged data are shown in the figure above. All individuals were given equivalent dosages at the start of the study. After 6 hours, how many times lower is the average proton (H+) concentration in individuals treated with drug Q than in individuals treated with saline?
2.5
3.0
30
1,000
Which of the following occurs in the stroma of chloroplasts?
CO2 is fixed into organic molecules.
Sucrose is converted into starch.
Light energy is absorbed by chlorophyll.
Glucose is oxidized to provide energy for the cells of the plant.
Which of the following best characterizes a cross between a homozygous recessive individual and an individual with the dominant phenotype, but whose genotype is unknown?
Selective cross
Monohybrid cross
Dihybrid cross
Testcross
Which TWO of the following features distinguish viruses from prokaryotes and eukaryotes?
Viral genomes are composed of DNA or RNA.
Viruses are surrounded by a carbohydrate capsule.
Viral proteins are synthesized only by an infected host cell.
Viruses scavenge ATP from an infected host cell.
Which of the following biomes is correctly paired with the description of its characteristics?
Taiga: absence of tall plants and trees, low precipitation level, shallow topsoil, and permafrost
Tundra: presence of cone-bearing trees, high precipitation level, moderate to cool temperatures
Estuary: salt-marsh grasses, algae, and phytoplankton prevalent, variable water salinity
Chaparral: presence of grasses, scattered trees, and large herbivores, seasonal rains and droughts, equatorial latitude
Which of the following will best help maintain the diversity and abundance of organisms in a terrestrial ecosystem?
Introducing a new exotic species
Preventing habitat destruction
Eliminating predatory species
Removing weeds and other undesirable plants
Which of the following is an example of postzygotic reproductive isolation?
A species of hummingbird that feeds from a particular flower species cannot efficiently orient its bill to feed from a similar flower species in the same geographic region.
One species of toad breeds in early summer, while a similar species of toad occupying the same geographic range breeds in late summer.
The hybrid offspring of parents belonging to different equine species do not produce viable gametes.
Similar species of fish are found in adjacent lakes that formed after an ancient river dried up.
Which of the following cell types are most likely to have motile cilia on the surface?
Yeast and other fungi
Epithelial cells lining the mammalian trachea
Bacteria living in a host animal’s intestines
Spermatozoa
Molecular geneticists have created fruit varieties that will not ripen naturally, allowing the fruit to be shipped over long distances without being damaged. They do so by inactivating genes for the production of a hormone that causes the fruit to ripen. Which of the following practices will cause the fruit to ripen once it is received?
Introducing ethylene gas into shipping containers or storage rooms
Placing the fruit in complete darkness
Increasing the temperature to 40°C
Treating the fruit with the plant hormone auxin
A
B
C
D
Some species of pine trees are adapted to fires. Seeds are released after the cones are exposed to fire. Which of the following is an advantage of this strategy?
he seedlings will have less competition after the fire.
The fire eliminates herbivores in the area so the seedlings can grow faster.
The carbon dioxide left after the fire is used by the seedlings to enhance growth.
The top branches of the trees are untouched by the fire and create shade needed for seed germination.
A student is studying a certain species of bacterium. In this species, the student has identified a certain operon that is inducible. The student causes a mutation in the regulatory gene so that the repressor protein is not synthesized. The most likely result of this mutation is that the structural genes in the operon will
be transcribed only in the presence of the inducer
be transcribed only in the absence of the inducer
not be transcribed in either the presence or the absence of the inducer
be continuously transcribed in both the presence and the absence of the inducer
A researcher identifies a new species within the moist soil of a wooded area. The species exhibits bilateral symmetry, has internal body segmentation, and uses metanephridia to remove wastes from its blood and coelomic fluid. Based on these characteristics, the new species should be categorized in which of the following animal phyla?
Mollusca
Arthropoda
Annelida
Echinodermata
Most cases of Tay‑Sachs disease are caused by which of the following?
Accumulation of lead in the tissues of a toddler exposed to lead paint
Ingestion of too much alcohol by an infant’s mother during her pregnancy
Mutations in a gene encoding a particular lysosomal enzyme
A diet that includes too many foods with a high concentration of saturated fats and cholesterol
Male stickleback fish have a characteristic red belly coloration. To defend its territory, a male stickleback fish will attack other male sticklebacks or a model that has a red mark on its belly, even if the model does not look like a fish. Attacking a model that does not look like a fish is an example of which of the following?
Fixed action pattern
Habituation
Imprinting
Operant conditioning
A
B
C
D
In flowering plants, the seed leaves that may store carbohydrates for the embryonic plant are called
cotyledons
bracts
tendrils
stolons
The temperature at which the experiment was conducted
The catalytic activity of the enzyme
The concentration of bacteria in the stock solution
The adjusted pH of the enzyme solutions
Which of the following has provided the strongest evidence for the evolution of organisms?
The fossil record
The existence of trophic levels
Variation among species in the number of chromosomes
Inheritance of acquired characteristics
An isolated hillside in a temperate deciduous forest was used for an ecological study. The hillside was treated with defoliant and herbicides for one year. The dead organic matter was left to decay at the site. Which of the following statements most reflects what changes can be expected in the hillside forest environment?
There will be a decrease in the rate of water runoff and soil erosion from the hillside.
Secondary succession will occur.
There will be a decrease in plant biodiversity, but animal biodiversity will remain unchanged.
The nutrient levels in the soil will remain constant because no plants were using the nutrient resources.
The most common objection expressed by some individuals in the United States to the medical use of human embryonic stem cells is which of the following?
The cells may be infected with a pathogen that will be transmitted to the recipient.
Isolation of the cells is labor intensive and expensive.
Every stem cell line that is developed must receive a patent.
Isolation of the cells requires destruction of embryos.
The "beads on a string" analogy used to describe the structure of chromosomes refers to DNA-histone protein complexes called
ribosomes
nucleosomes
nucleoli
telomeres
Reproduction by binary fission occurs in which of the following?
bacteria
Algae
Viruses
Fungi
Which THREE of the following are features of meiosis that are most likely to contribute to genetic variation in a species?
Segregation of homologous chromosome pairs at anaphase I
Independent assortment of chromatids at anaphase II
The binding of random large and small ribosomal subunits to mRNAs
Exchange of DNA between homologous nonsister chromatids
Ether may be used for anaesthetizing fruit flies for genetic experiments. The fruit flies are typically anesthetized in an etherizer, a small chamber that contains an absorbent material onto which a few drops of ether are placed before introduction of the flies. Ether is volatile and highly flammable. In which of the following locations should the ether be added to the etherizer?
At a lab bench in the middle of the lab, because the ether smell will rapidly disperse in the large volume of air
In a fume hood, where the ether fumes are drawn to the outside of the building through an exhaust system
Outside the building, where fresh air and wind will remove the ether fumes
At a chemical safety cabinet with the door ajar, where the ether bottle is opened with one hand and the etherizer is held in the other hand
Which of the following physiological responses helps to reduce body temperature?
Contraction of skeletal muscle
Release of thyroid hormone
Activation of the sweat glands
Release of prostaglandins from the hypothalamus
Epithelial cells of the small intestine have folds called microvilli on the surface that faces the interior of the intestinal tract. Which of the following best describes the role of the microvilli?
The folds increase the surface area for the phagocytosis of food particles.
The folds increase the rate of nutrient absorption by the cells.
The folds allow the cells to increase the rate of cellular respiration.
The folds allow expansion of the small intestine after a large meal.
A type of selection that exists between certain inherited conditions and environmental pressures, such as between sickle cell anemia and malaria, that stabilizes the frequency of both alleles is called
behavioral isolation
ecological isolation
hybridization
balanced polymorphism
Which of the following statements about the stratospheric ozone layer is accurate?
The ozone layer helps to absorb infrared radiation, preventing it from reaching Earth's surface.
Accumulation of chlorofluorocarbons (CFCs) in the atmosphere has led to depletion of the ozone layer.
Depletion of the ozone layer is most apparent in atmospheric regions above the equator.
Scientists believe that if the use of ozone-depleting agents is stopped, the damage to the ozone layer will repair itself within five to ten years.
Which of the following is an example of a density-independent factor that affects a population?
Drought
Parasitism
Overcrowding
Predation
External fertilization is typically found in which of the following organisms?
Birds
Amphibians
Reptiles
Mammals
Which of the following graph types should be used to illustrate the percent of hospital-acquired infections (nosocomial infections) in patients that are caused by each of several different organisms in a single year?
A pie chart
A line graph
A stem-and-leaf plot
A histogram
Reptiles are more closely related to birds than to amphibians.
Humans and hamsters have a closer genetic relationship than do humans and chimpanzees.
Humans and chimpanzees diverged genetically more recently than humans and snakes diverged.
Fish should have fewer amino acid differences than do amphibians.
Which of the following substances can cross a biological membrane by simple diffusion without the assistance of transport proteins or channels?
Oxygen, O2
Glucose
Sodium ions, Na+
Chloride ions, Cl–
The changes in turgor pressure that cause the stomata of leaves to open and close result primarily from the reversible uptake and loss of which of the following ions by the guard cells?
Potassium
Sodium
Calcium
Chloride
The role of denitrifying bacteria in the nitrogen cycle is to
convert atmospheric nitrogen, N2, to ammonium, NH4+
convert nitrate, NO3–, to atmospheric nitrogen, N2
assimilate nitrite, NO2–, to amino acids and organic compounds
release ammonia, NH3, from amino acids and organic compounds
The concentration of a stock solution of sulfuric acid is 18 M. Of the following, which describes the correct way to prepare 500 mL of a 1 M solution of sulfuric acid?
Add 472 mL of cold water to 28 mL of the stock sulfuric acid.
Add 472 mL of hot water to 28 mL of the stock sulfuric acid while vigorously stirring.
Add 28 mL of the stock sulfuric acid to 400 mL of water, and add water to bring the total volume to 500 mL.
Add 28 mL of the stock sulfuric acid to 472 mL of water.
Which of the following is most likely true about the first cells that arose on Earth?
They used cilia for locomotion.
They were eukaryotes.
They were photosynthetic.
They were anaerobes.
An animal with three distinct body divisions, a pair of antennae, compound eyes, and six legs is most likely
a tunicate
a polychaete
an insect
a spider
The DNA for the coding sequence of a gene that codes for a polypeptide containing 120 amino acids contains a minimum of how many nucleotide base pairs?
4
120
240
360
Which of the following helps explain why the largest land animals living today are predominantly herbivores?
More energy is available at lower trophic levels.
Plants are at a higher trophic level than animals.
Plant matter is easier to digest than meat.
Biomagnification has killed off most of the large predators.
Of the following, which will be most important in ensuring the successful establishment of a new wildlife preserve or national park in a rural community?
A large number of endangered species in the park
The presence of an adequate number of concession stands and restrooms in the park
The cooperation of individuals who live in the area or have been displaced by the park
A designated annual hunting season in the park
Which of the following scientific theories is supported by the fact that mitochondria are enclosed by a double membrane and possess their own DNA?
Endosymbiotic theory
Lamarck's theory of evolution
Darwin's theory of natural selection
Pasteur's germ theory
In a germinating seedling, the shoot grows upward toward the light while the root grows downward into the soil. Which of the following correctly explains these phenomena?
The shoot exhibits positive phototropism; the root exhibits positive gravitropism.
The shoot exhibits positive gravitropism; the root exhibits positive phototropism.
The shoot and root both exhibit positive gravitropism
The shoot and root both exhibit positive phototropism.
Which TWO of the following are characteristics of triglycerides?
Each molecule is composed of fatty acids linked to glycerol.
Each molecule has a hydrophobic end and a hydrophilic end.
Triglycerides form bilayers spontaneously in aqueous solutions.
Triglycerides occur as both solids and liquids at room temperature.
A biologist reports the length of a captured snake as 105.030 cm. How many significant figures are in the measurement?
3
4
5
6
Individual 3 must inherit at least one allele for color blindness from her mother.
There is a 50% chance that individual 3 will express the trait of color blindness.
Individuals 1 and 2 must inherit the allele for color blindness.
Both individuals 1 and 2 could inherit the allele for color blindness from their father.
Humans, reptiles, birds, and fish all belong to the same
class
family
order
phylum
Which of the following is a greenhouse gas that is produced in abundance by livestock manure and that some farms are now burning to produce electricity?
Methane
Ozone
Carbon dioxide
Sulfur dioxide
The ecological role that an organism plays in the community is known as which of the following?
Biome
Niche
Ecotone
Territory
In a particular multicellular organism, the cells are connected in long filaments called hyphae, the cell walls contain chitin, and the cells are often multinucleate. The organism is most likely a
flowering plant
bacterium
fungus
protozoan
A certain animal species with specific habitat requirements is found in only a few small, isolated populations, which are located in protected wildlife preserves. Which of the following most likely poses the greatest threat to the species’ long‑term survival?
An appearance of genetic mutations in the populations
An increase in the size of the wildlife preserves
A decrease in the genetic diversity of the populations
An increase in the reproductive success of the animals
Sockeye salmon
Canada goose
Rocky Mountain elk
Monarch butterfly
Gray whale
Which of the following is true about all of the animals listed above?
They have backbones.
They have internal fertilization.
They excrete urea.
They migrate
In an attempt to understand human diversity, scientists are studying slight variations in individual DNA sequences from people around the world. This type of research is known as
DNA fingerprinting
bioinformatics
gene mapping
genetic engineering
An insect species lays its eggs on a specific type of plant leaf. The leaves hide the insect eggs from predators and protect them from the environment. As the eggs hatch, the insect larvae feed on the leaves. Which of the following best describes the relationship between the insect and the plant?
Commensalism
Mimicry
Mutualism
Parasitism
The fact that mutations of different genes can block different steps of a single metabolic pathway best supports which of the following?
The one gene–one polypeptide hypothesis
The operon model of gene regulation
Koch's postulates
Evolution of species
A horticulturist crosses two snapdragon plants that bear pink flowers. In addition to 83 pink-flowering plants, the offspring from the cross consist of 38 red-flowering plants and 40 white-flowering plants. Which of the following is the most likely mode of inheritance described above?
Multiple alleles
Simple autosomal dominance
Sex-linked recessive
Incomplete dominance
Which of the following best explains why epidemiologists suggest that a certain percent of the population should be vaccinated against any given contagious pathogen?
Medical officials know how many people need to be vaccinated so that vaccines in storage are not wasted.
Drug companies charge the government before making vaccines, and the government needs to recoup the money from patients.
If a sufficient number of people are vaccinated, unvaccinated people are less likely to encounter an infectious individual and become ill.
Vaccines are the only way to treat viral diseases, and officials want to vaccinate the people they expect to become infected by certain viruses.
Which of the following typically triggers an increase in the respiratory rate of an individual during exercise?
Glucagon-secreting cells in the pancreas detect a decrease in blood glucose.
Skeletal muscle cells detect a buildup of lactic acid.
Sensors in the aorta detect a decrease in blood oxygen.
Sensors in blood vessels and the medulla detect a decrease in the blood pH.
Exergonic and endergonic reactions in cells are interrelated in that
energy released from exergonic reactions can be used to power endergonic reactions
an exergonic reaction cannot occur without an equivalent endergonic reaction
reactants are often the same for both types of reactions
products are often the same for both types of reactions
Energy is transferred from glucose to the phosphate group.
Phosphorus is needed to break down glucose.
When ADP gains a phosphate ion, ADP loses energy.
Energy is stored in the form of ATP.
Which of the following biomes is characterized by the presence of a distinct winter season, fertile soil with litter, and precipitation that is distributed throughout the year?
Desert
Grassland
Temperate forest
Tropical rain forest
Which of the following processes is most likely responsible for the recent increase of pathogenic bacteria that cannot be killed by commonly used antimicrobial drugs?
Adaptive radiation
Genetic drift
Disruptive selection
Natural selection
Which THREE of the following essential elements for plant growth are obtained primarily through the roots?
Nitrogen
Magnesium
Carbon
Potassium
Acid precipitation can best be decreased by reducing the amount released to the atmosphere of which of the following?
Nitrogen oxides
Mercury
Carbon monoxide
Carbon dioxide
What was Antoni van Leeuwenhoek's major contribution to biology?
Developing a model for the atomic structure of the atom
Discovering cell walls in cork tissue and coining the term "cell"
Advancing the field of microscopy through the discovery of bacteria and protists
Creating the comparative method of organismal biology
Which of the following environments will most likely experience the longest-lasting effects from a major hurricane?
Estuary
Open ocean
Grassland
Deciduous forest
In the blood and tissue fluids, cholesterol is typically found in complexes with low-density lipoproteins (LDLs). Cells take up cholesterol when LDL receptors in the plasma membrane bind to the circulating cholesterol-LDL complexes. Cells do not take up cholesterol when there is an excess of free intracellular cholesterol. Which of the following is an example of a negative feedback mechanism by which cells can regulate the concentration of intracellular cholesterol?
When there is an excess of intracellular cholesterol, cells do not transcribe the gene encoding the LDL receptor.
When there is an excess of intracellular cholesterol, cells do not add cholesterol to their cell membranes.
When there is an excess of intracellular cholesterol, cells synthesize their own cholesterol instead of taking it up from the blood.
When there is an excess of intracellular cholesterol, cells secrete cholesterol into the blood and tissue fluids.
Which of the following will most likely disrupt the existing Hardy-Weinberg equilibrium in a very large population of rodents?
The population is increasing in size, and resources are not limiting.
The population is isolated from other populations of the same species.
.All females produce approximately the same number of progeny each breeding season, and the progeny all survive and successfully reproduce.
All females of reproductive age prefer to mate with males with long, bushy tails.
A
B
C
D
Which of the following is most likely to occur during prophase I of meiosis?
Homologous pairs of chromosomes migrate toward the equator of a dividing cell.
Each chromosome in a cell is copied and becomes a pair of chromatids.
Exchange of homologous DNA fragments occurs between sister chromatids.
DNA-histone interactions cause a gradual increase in chromosome packing.
Which of the following structures pumps blood out of the mammalian heart?
Atrium
Ventricle
Aorta
Pericardium
Gregor Mendel noticed that when he crossed two pea plants with tall stems, some of the offspring had short stems. Which of the following best explains his observation?
Linkage
Independent assortment
Segregation
Incomplete dominance
Which of the following best accounts for the complex regulation of gene expression in multicellular eukaryotic species?
The presence of a large number of genes
.The presence of promoter regions
A genome composed of many chromosomes
Cell- and tissue-specific gene expression
Which of the following pairs of scientists used bacteriophages, which are composed of only DNA and protein, to demonstrate that DNA is the heritable macromolecule that carries genetic information?
Matthias Schleiden and Theodor Schwann
Alfred Hershey and Martha Chase
James Watson and Francis Crick
George Beadle and Edward Tatum
Many songbirds winter in one ecosystem and migrate to another to breed. Which of the following is most likely to occur if the habitat in the wintering grounds of a migratory songbird is degraded by human activity?
The population of the birds in the wintering grounds will increase due to increased food supply.
The birds will change migration routes to compensate for the loss of wintering grounds.
The population size of the birds will decrease as fewer birds will return to the breeding grounds.
The birds will breed in the wintering grounds to save energy.
A volcano erupts, killing 87 percent of the members of a wildflower population. The original population had approximately equal numbers of pink and white flowering plants. Several generations after the eruption, only pink flowering plants are present in the population. Which of the following led to microevolution in this case?
Gene flow
Genetic drift
Geographic isolation
Polymorphism
Using DNA technology, researchers are engineering nitrogen-fixing bacteria that can live in the tissues of nitrogen-demanding plants, which would reduce the need to use chemical fertilizers. Which of the following crops would most likely benefit from this kind of research?
soy beans
alfalfa
green beans
corn
Which of the following provides the immediate source of energy to establish the proton (H+) concentration gradient across the inner membrane of mitochondria during aerobic respiration?
The reduction of NAD+ to NADH and FAD to FADH2
The hydrolysis of ATP to ADP + Pi
Oxidation-reduction reactions as electrons are passed sequentially along members of the electron transport chain
Substrate-level phosphorylation reactions that occur at several steps of glycolysis and the Krebs cycle
Which of the following best describes a difference between viruses and prions?
Viruses contain nucleic acid, but prions do not.
Prions reproduce sexually, but viruses do not.
Viruses are infections, but prions are not.
Prions contain membrane-bound organelles, but viruses do not.
To determine when the crime occurred
To allow the bystander to serve as a witness
To control for contamination from the bystander's DNA
To gather an even number of samples for DNA fingerprinting
Which of the following is an example of asexual reproduction in plants?
Self-pollination in pea plants
Production of fruit with many seeds, as in tomatoes
Production of many fern sporophytes from a fern gametophyte
Strawberry plants produced by runners from other strawberry plants
Which of the following best describes the relationship between populations and communities?
A community is composed of populations.
A population is composed of more species than is a community.
Populations exist independently of communities.
Communities and populations are equivalent.
Which of the following contributes most to the ability of water to serve as a solvent for salts and many biological molecules?
Every water molecule is composed of two hydrogen atoms and one oxygen atom.
Water molecules are bent, and there is an angle of 109.5° between the hydrogen atoms.
The oxygen region of a water molecule has a partial negative charge, and the hydrogen regions have partial positive charges.
Water molecules form hydrogen bonds with other water molecules.
Which TWO of the following are the best examples of allopatric speciation?
DNA sequence similarity suggests that the flightless cormorant found on the Galápagos Islands and the flighted cormorants on the mainland share a common ancestor.
A hinny is the viable, sterile offspring of a female donkey and a male horse and has characteristics of both parents.
In some snail species, a single mutation reverses the direction in which the shell coils, so that snails whose shells coil in opposite directions cannot mate.
The Isthmus of Panama separates two very similar populations of fish, the Cortez rainbow wrasse in the eastern Pacific Ocean and the blue-headed wrasse in the western Atlantic Ocean.
positive feedback
negative feedback
translocation
translocation
Which of the following is considered to be a risk factor for developing type 2 diabetes, a disease typically characterized by the unresponsiveness of cells to insulin?
Playing sports excessively
Eating a diet rich in high-fiber foods
Having a consistently low blood pressure
Being overweight
sex-linked
unlinked
linked
codominant
Which of the following processes is associated with a net decrease of plasma membrane?
Phagocytosis of a bacterium by a macrophage
Exocytosis of zymogen by cells of the pancreas
Active transport of Na+ and K+ by the sodium-potassium pump
Mitotic division of an epithelial cell
Which of the following organisms is most likely to produce hundreds of eggs, of which only a few will become adult animals?
snake
whale
bird
frog
Which of the following is a recommended safety practice in school biology labs?
All chemicals should be stored in metal cabinets because of the toxic dust and fumes produced by most chemicals.
Bacteria should not be used because of the danger of human infection by viruses that are carried by bacteria.
Chemical-resistant gloves and aprons are recommended when performing dissections for protection against preservatives used in the specimens.
Plastic, rather than glass, beakers and other laboratory ware should be used because of the danger of injury from broken glass.
Group P
Group R
Group S
Group T
